Reactive power control device has transistor switched on shortly after apex of half wave in which diode conducts, off after phase delay if effective reactive power of capacitor to be reduced

摘要

The device has antiparallel-connected semiconducting elements (T1, D1) conducting in one direction only for connecting the capacitor(s) to an a.c. network. An IGBT transistor (T1) is switched on shortly after the apex of the halve wave in which a diode element (D1) conducts and off at a phase delay of between null and 180 degrees later if the effective reactive power of the capacitor is to be reduced. The transistor and diode are each connected in series with a d.c. choke (L1,L2), whereby the choke inductances are different.